Synchronizing clutch construction



June 17, 1941. sdN Q 2,245,816

- *sYNcHRoNIzINe CLUTCH CONSTRUCTION l Filed Dec. 29, 1959 v I r My INVENTOR. D M I 0Z52 5 Z1 TTORNEYSJ memes June 17, 1941' srucnaomzmc cimcn cous'raocnou can 11. Peterson, Toledo, Ohio Application member :0, 1m, Serial No. 311,019

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This invention relates to synchronizing clutches in'which a shiitable clutch element embodies a toothed section and a friction section shiftable to en'gage the clutch-face with a complemental clutch face of another clutch element,

preliminary to the inter-engagement of jaw or toothed faces of said elements, and has for its object a particularly simple and economical construction of the shiftable clutch element.

It further has for its object a synchronizing clutch element embodying a toothed section anda friction section, the latter being in theform of a sleeve having a limited rotary movement relative to'the toothed section, the'sleeve beingpro-' vided with lengthwise slots, each formed with a widened intermediate portion, and the toothed section having radial posts or cam blocks exshaft, although, in so far as the invention isconcerned, the clutch may be used in any situation, where two elements are to be clutched together.

I designates the input shaft. which is Jour- [nailed suitably within a housing or gear box);

3 the output shaft mounted in axial alinement with the input shaft'l.

4 designates a gear on, and here shown as integral with, the input shaft l and meshing with a gear 5 on the countershaft -not shown, of a conventional change speed transmission gearing. The gear 4 is also for convenience a clutch ear or driving clutch element and formed with a friction clutch face I and a toothed or iaw clutch face 'I.. I designates a gear element rotatably mounted on the output shaft 3 and meshing with a gear 9 on the countershaft not shown.

tending into the slots and of such width as to slidably fit the end portions of the slots and permit the relative rotary movement when .in the widened intermediate portions of the slots, the

wider intermediate portion taking the, form of notches on opposite sides of each slot and. the cam posts or blocks coacting with the ends of the notches at different angles, when a shift is being made from a lower-gear into a higher gear,

' than when a'shiit is being made from a higher gear into a lower gear, or in other words, the angle of engagement of the end walls of the notch on one side of the slot is less than the angle of side of .the slot.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference'is had to the accompanying drawing in which like characters designate corresponding parts in all the views.

Figure 1 is a fragmentary sectional view through a transmission gearing embodying this synchronizing clutch.

Figure 2 is a fragmentary sectional view on line 2'-'-2, Figure l, partly in elevation.

Figure 3 is a fragmentary end view of the shiftable clutch element.

Figure 4 is a fragmentary view of the periphery of the friction section or sleeve, taken on line 4-4, Figure 1.

The clutch here illustrated is shown as located to connect the input and output shafts of a change speed transmission gearing in direct drive relation and in indirect drive relation. through a train of gears, with the shiftable clutch element splined to and shiftabie vengagement with the cam posts on the opposite V The gear 4 also is a clutch gear or driving clutch element having a friction face it and a toothed clutch face Ii.

l2 designates a double synchronizing clutch element, as a whole, for coacting with either the driving. clutch element 4 or a. The synchronizing clutch element. includes an inner or toothed section-l3 splined on and shiftable axially of the output shaft Land a friction section l4, in the form of. sleeve, mounted on the inner section II and having friction clutchfaces I. and ii atits-opposite ends'for coacting respectively with the friction faces 8 and IQ of the driving elements 4 and I. The clutch element It also includes a shifting collar ll encircling the sleeve l4 and connected to the inner section ll. The sleeve 14 and the toothed section I: are capable of relative rotary movement, within limits, for so positioning the mas to block or retard enga ement of the toothed faces I8 and ll of the inner section It with the toothed faces I and ii of the elements 4 and a respectively, until the speeds of the elements to be clutched together are synchronized.

One or the objects of this invention is the as-. sembly of thecollar l1 and the inner toothed section I I. In so far as the assembly feature is concerned, the invention'is pertinent to a single clutch as well as to a double clutch shiftable axially from neutral in opposite directions. The sleeve i4 is provided with lengthwise slots having widened central portions providing ,opposite end portions 20 and 2| for which the wider portions 22, 23 constitute entrances. The widened portions 22, '23 take the form of wide notches. The inner section II is provided with radial proiections or posts 24 extending into the slots and axially of the output normally arranged in the wider central portions thereof and shiftable into either end portion 20 or 2| and slidably fitting the same. These posts are provided with radial bores 2! opening through their outer ends. The collar 11 is i cured to the collar II, preferably v by welding, as

at 28. Thus, the shifting collar i1 and the inner section l3,of the clutch element 12 are fixedly assembled in an extremely simple and economical manner. The inner clutch section I2 is case assure I v is free to enter the end portion 20 of the slot to bring the clutch teeth It into interlocking en Basement with the clutch teeth I. When a shift is'being made down, say from third to second, the clutch section It is first shifted to the rightto neutral position, and then further to the right to first engage the friction face It of the sleeve section with the friction face ID of the clutch gear I. 'Now, as this clutch gear is rotating idly, through-the second speed ratio, and hence slower than the output shaft 2, the sleeve section I4 is rocked in 'a direction opposite to the arrow A .(Figure 4), so that the cam post 24 enters the hardened and then the hardened ends of the posts, or th skin at the ends of the posts machined off, the bores 25 then bored while using the collar I! with the passages 26.1sherein as guides for the tools. The innersection It is also provided with other radial posts 29 having radial bores for receiving spring-pressed poppets 20 coacting with an inner circumferential cam groove 3! in the sleeve section l4. These poppets form no part of the invention. They normally hold the sections so that the sections shift as a unit until synchronizing is effected through the friction section and then permit further axial shifting of the toothed sectionrelative to the friction section, as is well undertsood.

Preferably, the clutch faces I! and I of the sleeve section H are conoidal in general form,- but are interrupted transversely, as at 32, and when viewed, as shown in Figure 3, have the appearance of teeth with inclined top faces.

In operation, mume for the purpose of illustration that'the clutch l2 controls the second and third speeds ina three-speed transmission,

and a shift is to be made froni first speed into second speed, that is, the clutch I2 is to be shifted to the right (Figure 1) from neutral position to clutch the gear 8 with the output shaft 3, the shaft having previously been driven from the notch 22 and remains until the speeds synchronize, permitting the cam post to be shifted into the end portion 2| of the slot to engage the clutch teeth I! and II. when a shift is being rhade into the direct drive, but the input shaft l is being driven slower than the output shaft 2, or the output shaft acting as a driver through any gear ratio will cause the toothed clutch section ll'to rotate slightly ahead of the sleeve |4,- causing the cam post to enter the notch 22 and there remain until the speeds of the drive and output shafts synchronize, or the speed of the input shaft builds up to the speed of the output shaft,

or the speed of the output shaft drops down to that of the input shaft, permitting the cam post 24 to be shifted to the left, irrtmthe end portion 20 of the slot.

Thus, in a three-speed ample, the shift to third speed or direct drive is always a shift up from a lower speed, and henceor a shift down from third speed. A shift up into third speed may in effect be the same as a shift down, when the input shaft 2 is running slower or the output shaft is running as. a driver, as

countershaft in first speed forward, and the selecting and shifting mechanism operated to unclutch the first speed forward clutch preliminary to operating the clutch l2 into second speed forward. Upon shifting of the clutch element i2 to the right, the friction clutch face ll will first" engage the friction face Ill of the clutch gear I causing. said gear, ,which is rotatable snow output shaft 3, to shift the sleeve seodon'u-oir cumferentially in the, direction of the arrow a ingcollar l'l shifts the canrpost 24 into the end portion 2| of the slot, b in the clutch teeth "into interlockin'g'engagement with the clutch teeth II. The same action takes place when the shift is being made from second to third speed,

when the clutch I2 is first shifted back to neumtral, and then because. of the driving action,

through the friction clutch faces 4 and II, causes the can post 24 to initially enter the notch until 0nd to third, or from first to second, as slowing when coasting.

In a shift up, as from first to second, or from second to third, it is not necessary that the-synchronizer or friction section l4 do any work on the gear train and the clutch-driver 4 or 8, as the case may be, whetherthe shift is from secdown effect, due to bearing friction, wind resistance, etc. on the vehicle, will gradually slow down the gear train and the speeds will become equalised and finally cross-tounlock the section I! and the cam post 24 first carrying into the notch 22, and'then when the speeds synchronize, may

5 be readily shifted into the end portion 2| ofthe slot, if thespeed' is from first to. second, or into .the end portion 2|, 1: the shift is from second to third. Any pressure exerted on the shifting lever to the shiftin'g'collar ll merely applies the pressure to the friction section It harder to make the slowing down faster. For a fast shift, a certain amount of pressure is required, but the shift may be readily made in any event, if pressure on the n eds are synehroniledwwhen the cam post 7 the shifting lever is only enough to effect a negligible pressure or. braking effect on the friction section l4. The minimum value of the pressure required under these conditions, that is suflicient to slide the cam post 24 down the cam angle at the ends of the slot 22. The pressure required to dislodge the poppets II out of the groove 3| is usually greater than that required to move the cam post 24 out of engagement with the end.

walls of the notch 22. I Another feature of this invention is the form- I' transmission, for ex-,

less angle so as :to have ingoftheendwalls fl'of isnecessarytodislodgethecampostflfrome the blocking effectof the end wall of the notch 22, and hence for the reasons iust explained, the angular engagement is less on the end wall of the notch 22 than on the end wall of the notch 23 in which the cam post it is located, when a shiftismade downfromthirdtoseeondorup from second to third when the input shaft is rotating slower than the outputshaft 3.

Shifting down from a higher to a lower sear ratio in this instance, from third to second speed requires suflicient friction between the cam post 24 and the friction section ll to overcome the frictional dragon .the gear train,.as well as surfaces 22 and 23' of the notches 2 the inertia of. the gear train, to speed the gear train up to the higher speed, until the speeds are equal; then, as the campost 24 slides down the cam angle 23, the train of gears must be speeded up still slightly more. If the cam is too abrupt or flat, shifting will be mmclllt. since this last increase in rotation of the gear train is accompiished by sliding down the. cam angle. Thus for respectively, but the blocks would onset with thesameanglesorwiththesameeffectifthey were round blocks or rollers. The corners of the blocks 2'! are, however, usually of the sameangles as the end surfaces and 23'.

What I clahn is: V

1. Inatransmissiongearingincludingashaft and an element to be clutched to the shaft havingafrictionface andatoothedface,thecombination' of a clutch element including a toothed section rotatable with the shaft and shiftahle axially thereof and having a toothed face, and a friction section in the general form of a sleeve encircling the toothed section and having a friction'face for coacting with the former friction face, a shifting collar encircling-the sleeve. the

' sleeve being formed with lengthwisemlots and the a shift down the cam angle must be steep to ac-' I complish the shifting and the limit of steepness determined by the point at which the cam post 24 will not lock and hold while there is As the engine or input shaft of a motor vehicle always rotates inthe same direction, a l asalnst the slotpor'tions a and the collar with a radial passage therethrough alined with the bore, radial pins extending through the passages of the'collar' and into the radial bore of the toothed section and snusly lit- -andanelementtoheclutchedtotheshafthavencirclingthe toothedsectionandhaving afric- 4' s,24s, e 1'e fol med mm intermediate widened portions and the toothed section having cam posts extendin:

lnto the slots and normally arranged in the 1 widened portions". each and the ends '0! i the widened portion: being arranged to enact at a less angle on one side 0: the slot than. the 1 angles of coactlon on theopposlte side of the 5: Bear ratio.

. slot, whereby during shitting mm a higher gear ratio, less shiltlnl force is required to slide the cam posts out of the intermediate widened portions of the slots than when shifting to a. lower CARL D-Pm'fimson 

